[Gllug] Hard disk recommendations please

[Richard Jones]

On Thu, Dec 02, 2010 at 11:24:29AM +0000, Patrick Moody wrote:
> I am planning to expand the capacity of my server, which runs Ubuntu
> 10.04 LTS.  I'd like to add a 1TB disk of the low power/green sort,
> set up LVM on it and copy the contents of the existing(non LVM) 750GB
> to it, before combining the 2.

"Combining" in what way?

I'm a bit worried about this plan over all, since there is no
redundancy.  While I'm sure you regularly back up the disks it's still
better to add some redundancy (in addition to backups) so that you
won't have to handle a painful and lengthy restore when one of the
disks fails.

Given that, I'd buy 2 of the 1TB disks and put them together in a RAID
1 configuration, yielding about 1TB of usable space, with everything
being duplicated on each disk.  Or 2 x 2TB disks if you can afford it.

This leaves your old 750GB disk with nothing to do.

> Firstly; any comments on the viability of my plan.  Particularly any
> advice about using LVM as it's my first time doing it it seems like it
> should meet my needs in this case.

LVM is great for flexibility.  In this case I'd suggest LVM on top of
software RAID (/dev/md0).  For one thing this will allow you in future
to live pvmove the data to another pair of disks.  Or lvextend across
another pair of disks.

> Secondly; Amazon are selling a Western Digital Caviar Green 1Tb for
> £40 inc delivery, which seems like a pretty good deal.  However I read
> some reviews of the caviar green series suggesting their power saving
> features aren't well suited to use in NAS boxes running Linux because
> the heads get parked after 8 seconds out of use and are then un-parked
> repeatedly.  This causes the drives to work themselves to an early
> death, according to the reviewers.  Is this likely to be a problem in
> a normal server setup as well, or is the issue more likely confined to
> NAS boxes?

I'd be a bit surprised if you couldn't configure this timeout using
hdparm.

Rich.

-- 
Richard Jones
Red Hat
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